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| author | Takashi Iwai <tiwai@suse.de> | 2025-05-16 10:08:16 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-06-04 14:42:19 +0200 |
| commit | 74d90875f3d43f3eff0e9861c4701418795d3455 (patch) | |
| tree | c610b514a4bf6f232adf0b301c6d85a0ef5dc759 /include/sound | |
| parent | b5bada85c181fef06bafc61f0677577d54013601 (diff) | |
| download | linux-74d90875f3d43f3eff0e9861c4701418795d3455.tar.gz linux-74d90875f3d43f3eff0e9861c4701418795d3455.tar.bz2 linux-74d90875f3d43f3eff0e9861c4701418795d3455.zip | |
ALSA: pcm: Fix race of buffer access at PCM OSS layer
commit 93a81ca0657758b607c3f4ba889ae806be9beb73 upstream.
The PCM OSS layer tries to clear the buffer with the silence data at
initialization (or reconfiguration) of a stream with the explicit call
of snd_pcm_format_set_silence() with runtime->dma_area. But this may
lead to a UAF because the accessed runtime->dma_area might be freed
concurrently, as it's performed outside the PCM ops.
For avoiding it, move the code into the PCM core and perform it inside
the buffer access lock, so that it won't be changed during the
operation.
Reported-by: syzbot+32d4647f551007595173@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/68164d8e.050a0220.11da1b.0019.GAE@google.com
Cc: <stable@vger.kernel.org>
Link: https://patch.msgid.link/20250516080817.20068-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/sound')
| -rw-r--r-- | include/sound/pcm.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/sound/pcm.h b/include/sound/pcm.h index 2a815373dac1..ed4449cbdf80 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -1427,6 +1427,8 @@ int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream, struct vm_area_s #define snd_pcm_lib_mmap_iomem NULL #endif +void snd_pcm_runtime_buffer_set_silence(struct snd_pcm_runtime *runtime); + /** * snd_pcm_limit_isa_dma_size - Get the max size fitting with ISA DMA transfer * @dma: DMA number |